id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
30143	Django query abrupt behaviour	Shashank Parekh	nobody	"{{{
class Model:
     a = models.CharField(max_length=100)
     b = models.CharField(max_length=100)
     c = models.DateTimeField(max_length=100)


query1 = Models.objects.filter(Q(a__in=['1']) | Q(b__in=['2'])).filter(**{'c__gte': timezone.datetime(2019,1,1), 'c__lte': timezone.datetime(2019,2,1)}).order_by('-c')

query2 = Models.objects.filter(Q(a__in=['1']) | Q(b__in=['2'])).filter(**{'c__gte': timezone.datetime(2019,1,1), 'c__lte': timezone.datetime(2019,2,1)})
}}}

**query2 is executed perfectly but query1 is timing out.**

I did explain on query1 and ran the query(on `explain()` output) on MySQL directly and it worked absolutely fine.
query1 worked fine in django1.8 but not in django2.1.

Although, If I use `query1.iterator()` it is working.

**Mysql version = 5.6.39**
**No of rows in table = 5M**
"	Bug	closed	Database layer (models, ORM)	2.1	Release blocker	invalid			Unreviewed	0	0	0	0	0	0